fuse: on darwin, read the FUSE device with a single goroutine.
fuse: on darwin, read the FUSE device with a single goroutine.

This is necessary to work around apparent bugs in the OSX FUSE
implementation.

cmars/tools,keybase/go-fuse,cmars/tools,keybase/go-fuse,cmars/tools,cmars/tools,keybase/go-fuse